Biosafety level 9 does not exist. Biosafety levels, also known as biological safety levels or BSLs, are classifications of safety precautions necessary to be applied in the clinical microbiology laboratory depending on specific pathogens handled when performing laboratory procedures. There are four biosafety levels, each with specific controls for containment of microbes and biological agents. The primary risks that determine levels of containment are infectivity, severity of disease, transmissibility, and the nature of the work conducted. The four biosafety levels are:

• Biosafety Level 1 (BSL-1): Suitable for experiments involving agents of no known or of minimal potential hazard to laboratory personnel and the environment. The laboratory is not separated from the general traffic patterns of the building. Work is generally conducted on open bench tops and special containment equipment is not required or generally used.

• Biosafety Level 2 (BSL-2): Controls microorganisms generating "moderate hazards" to the laboratory and the community. This type of work can be done in clinical, diagnostic, teaching, research, or production facilities. Here, the precautions undertaken in BSL-1 labs are followed, as well as additional measures including access restrictions, PPE, and biological safety cabinets.

• Biosafety Level 3 (BSL-3): Appropriate for work involving microbes which can cause serious and potentially lethal disease via the inhalation route. This type of work can be done in clinical, diagnostic, teaching, research, or production facilities. Here, the precautions undertaken in BSL-1 and BSL-2 labs are followed, as well as additional measures including controlled access, decontamination of waste, and specialized ventilation systems.

• Biosafety Level 4 (BSL-4): The highest level of biosafety precautions, and is appropriate for work with agents that could easily be aerosol-transmitted within the laboratory and cause severe to fatal disease in humans for which there are no available vaccines or treatments. BSL-4 laboratories are generally set up to be either cabinet laboratories or protective-suit laboratories. In cabinet laboratories, all work must be done within a class III biosafety cabinet.

Therefore, there is no such thing as biosafety level 9.